In order to increase the power and the efficiency of gas turbines, the entry temperatures in modern gas turbines become higher and higher. For that reason, an increasing number of turbine components need some sort of cooling structures to achieve an acceptable lifespan. However, an increase in e.g. cooling air usage has a negative effect on the efficiency of the gas turbine such that more efficient cooling methods are required. For example, this can be achieved on smaller components by the use of complex cooling features formed into the components. However, for larger structures made of sheet metal, for example, the cooling methods which are available are much more limited than those components that are manufactured by precision casting or machining, etc.
Previously fabricated structures for gas turbine components have been made suitable for use in higher temperature environments by manufacturing the turbine components from evermore exotic materials. The use of such exotic materials is expensive and limited by the available materials.
Alternatively, it is known to use double-skin components which are spaced apart from each other such that cooling fluid streams between the components. The design of such double components is costly due to the complex arrangement and the alignment between each other and limits the design and profile flexibility of the turbine components.
U.S. Pat. No. 4,168,348 discloses a perforated laminated material for a combustion chamber of a gas turbine. The material comprises at least two abutting sheets of a perforated material, the perforation being out of alignment and interconnected by a series of channels formed on or both of the abutting surfaces of the abutting sheets.
U.S. Pat. No. 3,584,972 discloses a sheet material of a controlled porous characteristic made up of two or more metal lamina bonded together, the lamina being photo etched or otherwise machined to define pores through the lamina and also passages between the abutting faces of the lamina. The sheet may be used for turbine blades or other hot parts of the gas turbine.